FOREWORD This book came about as a result of two events: an exhibition on the Solvay Physics Councils, held in Brussels in May 1995, and a conference on the same theme which took place at the Free University of Brussels (ULB) on May 1Oth 1995. A book was published in French in conjunction with the exhibition, and much of the present publication is taken from that book. In addition, we have included some of the papers presented at the conference, as we believe they add a further dimension to the history of the Councils. The French term, Conseil Solvay, is usually translated into English as Solvay Conference or Congress. We have elected to retain the particular connotations of the French word Conseil by translating it instead as Council. The Councils were, after all, no ordinary conferences. Only a limited number of participants was invited, hand picked by a scientific committee, who for five to six days took an active part in the sessions and the long discussions that followed. Each day, one or two physicists would present a paper on a subject that had been chosen by the committee to fit in with the overall theme of the Council. The word Conseil expressly implies the gathering of an elite to engage in debate.

Inhalt
First Part Background to the Solvay Councils.- Ernest Solvay: The System, the Law and the Council.- Rutherford, the Cavendish Laboratory and the Solvay Councils.- Paul Langevin and the French Scientists at the Solvay Conferences.- The Solvay Councils and the Nobel Institution.- The Organisation of Science in the 19th Century.- Physics Prior to the First Council.- Second Part The Birth of Modern Physics.- The First Solvay Council.- 1913 1921: From the Second to the Third Council.- 1927: The Fifth Council.- The Debate Between Einstein and Bohr, or How to Interpret Quantum Mechanics.- 1933: The Seventh Council.- A New Era.- Notes.- The First Twelve Solvay Councils of Physics.- The Participants to the First Seven Solvay Councils of Physics.- Photographs Credit.- Authors.